This relates generally to imaging devices, and more particularly, to imaging devices with column circuitry.
Image sensors are commonly used in electronic devices such as cellular telephones, cameras, and computers to capture images. In a typical arrangement, an electronic device is provided with an array of image pixels arranged in pixel rows and pixel columns. Circuitry is commonly coupled to each pixel column for reading out image signals from the image pixels and supplying bias signals to the image pixels. The readout circuitry sometimes includes a current mirror circuit.
In some situations, image signals from a pixel array can exhibit noise such as fixed pattern noise related to the operation of current mirror circuits on one or more pixel columns. This type of fixed pattern noise can reduce the quality of captured image data and may reduce the percentage yield of viable image sensors in situations in which image sensors are being produced in large numbers.
It would therefore be desirable to be able to provide imaging devices with improved column circuitry.